In today's digital age, companies selling goods and services to consumers must engage in online marketing and sales over the Internet to be competitive. For example, many large department stores that traditionally have brick and mortar stores also have sophisticated web sites providing detailed product information and the ability for visitors to purchase products online. Furthermore, many companies have large marketing budgets directed to online marketing, including marketing on their web sites.
One of the key challenges facing these companies is how to evaluate their online marketing efforts. Online activity, such as web site traffic and online sales may be used as a measure of online marketing efforts. However, online marketing may impact in-store sales as well as online sales. For example, a consumer may view product information online and then go to the brick and mortar store to see the product and ultimately purchase the product at the store. It is very difficult to track the impact of online marketing when purchases are made in this manner. To optimize marketing efforts and justify spending for online marketing, companies need to have the ability to accurately capture the impact of their online marketing efforts on offline sales.